The
majority of ‘Hard Turning' applications require the removal of what
used to be considered a grinding allowance.
This commonly ranges from 0.1 - 0.5 mm. In
order to reduce the cost of ‘Hard Turning’, David Richards have
developed 3 products:-

DOUBLE
EDGE (DE) PRODUCTS

In
order to provide strength to the cutting edge, even where very light
cuts are required, the best performance
is achieved by Negative Rake cutting tool inserts. This type of
geometry enables David Richards to produce
an insert with PCBN brazed to the corner of the base hard metal
insert, extending from top to bottom. In
this way two cutting edges can be produced for the material cost
of one. Supplied from stock ‘DE’ style cutting
tool inserts are available in Grades DR-50,
DR-80 and DR-450 with radius
sizes from 0.2 - 1.2 mm.

If
negative geometry or ‘Double Edge’ style cutting tool inserts are
not suitable for the application, single side
inserts are available with a cutting edge of 1.25 mm. This product
style incorporates positive geometry inserts
commonly used in standard boring bars and smaller machine tools.
Supplied from stock these products are available
in Grades DR-50,
DR-80 and DR-450 with radius sizes from 0.2 - 1.6 mm.